Cameras, such as closed captioned television (CCTV) security cameras, are increasingly used to prevent crime. In some cities, tens of thousands of security cameras are installed to watch over suspicious persons or activities, thus raising a high expectation from the general public. However, such expectation had often been met with a poor result owing to the short attention span of a person monitoring the surveillance footage as well as the lack of manpower required to review the lengthy video footage. For instance, the attention span of an average person is about 20 minutes, and it can take a sizable manpower to review the surveillance footage recorded by several camera/recording devices 24 hours a day.
Video synopsis is an approach to create a short video summary of a long video. According to the method, moving objects are followed (e.g., tracked, traced, recorded, etc.), and video streams capturing the movements of the moving objects are converted into a database of objects and activities. Once the database is formed, when a summary of the moving objects is required, the moving objects from the target period are collected and shifted in time to create a much shorter synopsis video, in which the moving objects and activities that originally occurred in different times are displayed simultaneously.